1. Field of the Invention
This invention relates to a liquid spray nozzle and, in particular, to a spray nozzle having a reversible spray tip ideally suited for airless spraying.
2. Brief Description of the Prior Art
Airless spraying is finding increasing acceptance in the industry because precise spray patterns can be achieved by this system. Airless spraying requires the use of a very minute and precisely shaped orifice spray member which, typically, is formed of tungsten carbide. The orifice spray member has a through passageway with a convex discharge face but having a V-groove which intersects the through passageway, thereby providing a flat spray pattern.
A common difficulty experienced in airless spraying is that minute solids such as impurities and precipitates in the liquid become clogged in the orifice, necessitating its cleaning. A number of approaches have been developed to reverse the orifice tip member in the assembly whereby the liquid pressure can be applied to dislodge the solids from the passageway. Generally, however, the nozzle heads which permit reversal of the orifice tip member are relatively complex with a substantial number of parts, adding to the cost of assembling and increasing the probability of failure in use. Various constructions which have been employed for reversal of the spray tip member have included a housing that rotatably supports a spherical turret between opposite annular seals. The orifice tip member is removably mounted in the turret member. Other embodiments have included mounting of the turret member in a cylindrical turret that is received in a body having a large diameter spray discharge opening whereby the orifice tip member can be removed from the turret member through the spray opening in the front of the nozzle without removing the nozzle from the supporting barrel of a spray gun and the like.
Other approaches for the reversing of the orifice spray tip member have included mounting the spray tip member on a slide that can be removed and reversed in its assembly with the housing.
Generally, the aforementioned attempts for reversibility of an orifice tip member have required relatively complex and costly construction. It is, therefore, desirable to provide a relatively inexpensive unit which provides for facile reversal of the orifice tip member in the spray nozzle.